JPS5838526B2 - Gokubososen Inoseizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a practical method for producing ultrafine fibers in which a part of the constituent components of the fibers are dissolved and removed by washing with water.

Recently, as clothing products become more sophisticated and diversified, attempts have been made to improve the texture by making fibers ultra-fine, and as the development of applications for synthetic paper and non-woven fabrics progresses, there is a desire to develop methods for producing synthetic fibrillar ultra-fine fibers. It has become.

However, the fine denier fiber obtained by ordinary spinning methods has a limit of about 0.5 to 1.0 denier at most, and 0.5 to 1.0 denier at most.
The method for producing ultrafine fibers of 1 denier or less is as follows:
Although various methods have been proposed, the current situation is that they have not yet been put into practical use.

For example, Japanese Patent Publication No. 44-21167 proposes a method of manufacturing ultrafine fibers by mixing and spinning two or more different components and then dissolving and removing one or more components with a specific solvent. Because organic solvents are used, there are safety issues such as odor and flammability.Furthermore, the solvents are limited depending on the components to be mixed and spun, and safety equipment and conditions are required for dissolving and removing them. It was difficult to put it into practical use because of the limitations.

The present inventors believe that the problem with the conventional method is that an organic solvent must be used as the solvent. The manufacturing method of ultrafine fibers by mixing and spinning the following components is not only extremely easy to put into practical use, but also can be dissolved and removed in the water washing process that is normally applied to fibers and textile products, depending on the application, so it is considered to be of great value. As a result of extensive research on polymer compounds that are easily soluble in water and can be mixed or composite-spun with other polymer compounds that have fiber-forming ability, we found that the average degree of polymerization is 50-300 and the degree of saponification is 50-300.
The present invention was completed by discovering that 80 mol% polyvinyl alcohol (hereinafter referred to as PVA) is water-soluble and heat-meltable, and also has fiber-forming ability.

That is, in the present invention, PVA having an average degree of polymerization of 50 to 300 and a degree of saponification of 50 to 80 mol% and a polymer compound having fiber-forming ability are mixed-spun or composite-spun, and if necessary, after being subjected to stretching heat treatment. , the obtained fibers are washed with water and PV
This is a method for producing ultrafine fibers characterized by dissolving and removing A.

Average degree of polymerization used in the present invention 50-300, degree of saponification 5
0 to 80 mol% PVA can be obtained, for example, by polymerizing vinyl acetate to an average degree of polymerization of 50 to 300 in an alcohol having a chain transfer constant of 20X10-' or more at the polymerization temperature, and then removing the solvent while heating. After expelling the mixture, it can be produced by mixing and dissolving in anhydrous methanol and adding an alkali to deacetate the mixture.

The thus obtained PVA with an average degree of polymerization of 50 to 300 and a degree of saponification of 50 to 80 mol% can be heated to a temperature of 100 to 240°C by using PVA alone or by adding an appropriate amount of a fluxing agent to the PVA.
Since it can be heated and melted at any temperature, it can be melt-mixed or composite-spun with most heat-melting polymer compounds such as nylon, polyester, polyethylene, polypropylene, and polyparaoxybenzoate.

In addition, since the PVA used in the present invention with an average degree of polymerization of 50 to 300 and a degree of saponification of 50 to 80 mol% is soluble in water at room temperature, it can be mixed and spun with ordinary PVA or polyfural using water as a solvent. Furthermore, since it is soluble in organic solvents such as acetone, dimethylacetamide, and dimethylformamide, it can be mixed and spun with acetate, PVC (dry method), polyacrylonitrile, and polyurethane, which are spun from a spinning dope using these solvents.

In the present invention, after mixing or composite spinning such specific PVA and a polymer compound having fiber-forming ability, the resulting fibers are washed with water to dissolve and remove the PVA constituting the fibers. PVA must not only be able to be mixed with other polymeric compounds having fiber-forming ability or composite-spun, but also be able to be easily removed by washing with water after fiber formation.

However, PVA with an average degree of polymerization of less than 50 is not only difficult to manufacture, but also difficult to mix and spin with other polymers.On the other hand, if the average degree of polymerization exceeds 300, the thermal meltability deteriorates, making it difficult to mix and spin PVA with other polymers. Melt-mix spinning with the compound becomes difficult and cannot be applied to the present invention.

Furthermore, even if PVA has an average degree of polymerization of 50 to 300, if the degree of saponification is outside of 50 to 80 mol %, it will lose either heat-melting or water-solubility properties, and thus cannot be applied to the present invention.

Therefore, the PVA applied to the present invention has an average polymerization degree of 50
-300 and a degree of saponification of 50-80 mol%.

Such specific PVA easily dissolves in water even if 50% or less of a fluxing agent such as polyhydric alcohols or urea derivatives is mixed with the PVA. The agent may be added in an amount of 50% by weight or less based on the PVA.

Average degree of polymerization used in the present invention 50-300, degree of saponification 5
0 to 80 mol% of PVA or PVA to which 50% by weight or less of a fluxing agent is added can be mixed with other polymeric compounds having fiber-forming ability by melting or using a solvent. Since they are not completely mixed and each retains its own unique components, the fineness of the resulting ultrafine fibers can be adjusted as desired by selecting an appropriate mixing ratio during mixed spinning.

In the case of melt spinning, composite spinning may be performed in which the specific PVA is used as a sea component and other polymer compounds are used as an island component.

The mixed spun fibers or composite spun fibers thus obtained can be easily stretched and heat treated (shrinked) if necessary, so that the fineness of the resulting fibers can be further adjusted as desired.

Average degree of polymerization used in the present invention 50-300, degree of saponification 5
PVA of 0 to 80 mol% differs from ordinary fiber raw material polymers in that it has very low orientation, so even if it is stretched during melt spinning, dry spinning, or wet spinning, or stretched as a post-treatment, it will not remain in the fiber. Since the PVA component is in a non-aligned state, it is very easy to dissolve and remove the PVA component by washing with water.

In the present invention, specific PVA and a polymer compound having fiber-forming ability are mixed or composite-spun, stretched and heat treated if necessary, and then the fibers are washed with water to dissolve and remove the PVA. During spinning, specific PVA can be used alone or mixed with 50% by weight or less of a flux, heated and melted to form chips, and then mixed with other polymeric compounds capable of forming fibers and melted and then subjected to dry or wet spinning. can.

Furthermore, if the obtained fibers are subjected to treatments such as drawing and heat treatment, and then immediately washed with water, ultrafine fibers with PVA dissolved and removed can be obtained. It is also possible to directly produce ultrafine fiber products by dissolving and removing residual PVA during processing of the fabric obtained after processing such as weaving and knitting.

If PVA is completely dissolved and removed from the ultrafine fibers obtained by the method of the present invention, the handling of the yarn or the processability during weaving and weaving will be reduced, but the fibers with some or all of the PVA remaining will be In addition to having good properties, fabrics made from such fibers have an excellent feel, unlike fabrics made from ultrafine fibers in which PVA has been completely dissolved.

Furthermore, if the present invention is carried out by a mixed spinning method, fibrillar ultrafine fibers can be easily obtained, and in addition, PVA to be dissolved and removed can be easily obtained.
Since it has rewetting adhesive ability, it is possible to make ultrafine fibers useful for paper making, nonwoven fabrics, etc. by controlling the degree of water washing.

In this way, the fibers obtained by the method of the present invention are composed of a specific PVA that is easily dissolved in water as one component.
Not only is it easy to put into practical use, but specific PVA
It is also possible to utilize the adhesive ability, which is a characteristic of
The fibers of the present invention have a wide range of applications and are of great value.

Next, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these Examples unless it goes beyond the gist thereof.

In the examples, "parts" simply refer to parts by weight.

Example 1 PVA 10 with an average degree of polymerization of 250 and a degree of saponification of 60 mol%
0 parts and 10 parts of glycerin were heated, mixed, melted, and extruded to obtain chips.

This chip completely melted at 160°C and was completely dissolved and dispersed in water at 20°C or higher.

The chip was made of polyethylene (molecular weight 48,000, melting point 12
0 to 122°C) in various weight proportions, and put it into a melt extruder with a screw diameter of 30mm and a length of 450mm, and
When the mixture was melt-kneaded at 0°C and spun using a nozzle with a hole diameter of 0.6 mm and 40 holes, fibers of various weight ratios could be wound up at speeds of 100 to 500 i/min.

Of these, 70 parts of the chips and 30 parts of polyethylene were mixed and a raw fiber of 11.0 denyl was spun at 200 m for 7 minutes, and when it was drawn to double the original fiber size using a hot drawing machine at 140°C, it was 5.8
A drawn fiber having a denier, a strength of 2.79/d, and an elongation of 23.8% was obtained.

When this fiber was washed in running water at 30° C. for 3 minutes, most of the water-soluble components contained therein were dissolved in the water, and fibrillar polyethylene fibers with a diameter of about 0.6 μm were obtained.

Example 2 50 parts of PVA with an average degree of polymerization of 120 and a degree of saponification of 72 mol% and ordinary PVA (average degree of polymerization of 1700 and saponification degree of 99%)
．． 95 mol %) and poured into water, heated, dissolved and filtered to obtain a spinning stock solution with a solid content concentration of 18.0%.

This stock solution was subjected to the usual vinylon wet spinning conditions using a saturated aqueous solution of sodium sulfate as a spinning bath, and the immersion length was 1.2 rr.
The fibers were spun at a speed of 8 m/min, with a spinning stretch of 3.0 times, and subjected to conventional moist heat treatment (sodium sulfate 25 o/l, sulfuric acid 5 da/l,
90°C, 1 minute) and drying, then 230°C
It was hot stretched 3.5 times in heated air at 238°C, further hot stretched 3.5 times in heated air at 238°C, and further heat-shrinked by 5% in heated air at 238°C.

This heat-treated fiber has a denier of 2.5 and a strength of 3.49/d.
The elongation was 16.8%.

As a result of washing this fiber in running water at 30°C for 2 minutes,
The water-soluble components contained were completely eluted into water, and fibrillar PVA fibers with a diameter of about 0.8 μm could be obtained.

Example 3 PVA with average polymerization degree of 80 and saponification degree of 57 mol% is 95%
It was completely dissolved in acetone and also dissolved in water at 20°C.

50 parts of the PVA and 50 parts of acetate flakes (cellulose diacetate, degree of polymerization 190, degree of acetylation 54.3%) were dissolved in 95% acetone to obtain a 26.5% spinning stock solution, which was then used for ordinary acetate dry spinning. Approximately 100 depending on conditions
Approximately 350 m from the top of the spinning tube into which heated air at ℃ was introduced.
Spinning took 7 minutes.

When the obtained fibers were washed with water at room temperature, they had a diameter of approximately 1μ.
fibrillar acetate fibers were obtained.

Example 4 PVA with an average degree of polymerization of 250 and a degree of saponification of 60 mol% was used as the sea component, and the density was 0.91. melt index 32
/min polypropylene is used as the island component, and the discharge amount is P
VA4.6f/min, polypropylene 4.4? /min, and using a nozzle with 10 holes, a composite fiber in which the number of island components in one filament is 20 was heated for 400 m.
Spun at 210° C. at a speed of 7 minutes.

The obtained fiber was hot-stretched 7 times at 190° C. to obtain a drawn fiber having a denier of 2.89, a strength of 3.71/d, and an elongation of 18.5%.

When this fiber was washed in running water at 40°C, the PV
Most of the portion A was eluted, and ultrafine polypropylene fibers of 0.07 denier were obtained, and the strength thereof was 4.6 f/d.

Claims (1)

[Claims] 1 Average weight 50-300, degree of saponification 50-80 mol%
Polypynylanonitrile and a polymer compound having fiber-forming ability are mixed-spun or composite-spun, and if necessary, stretched,
A method for producing ultrafine fibers, which comprises heat-treating and then washing the resulting fibers with water to dissolve and remove polyvinyl alcohol.